Hybrid vehicles, electric vehicles (EV), fuel-cell vehicles (FCV), etc., are known as examples of vehicles including at least one electric storage device, such as a high-voltage battery and a capacitor, and at least one motor-generator for driving.
A vehicle of this type generally includes a regenerative braking apparatus that operates the motor-generator such that the motor-generator generates a driving force while consuming electric power when the vehicle is being driven and generates electric power to regenerate kinetic energy when the vehicle is decelerating.
When the vehicle is decelerating, the regenerative apparatus causes the motor generator to apply a regenerative brake to the vehicle in accordance with a required deceleration. Alternatively, a braking force is generated by both a frictional brake and the regenerative brake applied by the motor-generator in accordance with the brake operation performed by a driver.
In the case in which the frictional brake and the regenerative brake are both applied, regenerative cooperative brake control is performed in which a braking force of the frictional brake is reduced or eliminated while a braking force of the regenerative brake applied by the motor-generator is increased by an amount corresponding to the reduction in the braking force of the friction brake. Thus, the kinetic energy is recaptured by the motor-generator.
In addition, an apparatus for adjusting a driving/braking force by controlling the motor-generator when the tires slip due to a brake operation or an accelerator operation or when an anti-skid braking system (ABS) or a traction control system (TCS) is activated is known.
Further, Japanese Unexamined Patent Application Publications Nos. 7-059202, 10-66248, and 2005-94883, for example, suggest apparatuses for shutting off circuits through which a high-voltage current flows (high-voltage circuits) with relay circuits to prevent short circuits in the event of a vehicle collision or rollover.